GB191223940A - Improved Means for Indicating when the Flow of Current in an Electric Circuit is Interrupted or Varied. - Google Patents

Abstract

23,940. Berry, A. F. Oct. 19. [Cognate Application, 27,534/12.] Heating by electricity.-A device for con. nexion in series with an electric heating- apparatus to indicate roughly the strength of current being used, consists of a low-voltage electric lamp shunted across a low resistance. The voltage across the device may be of the order of a quarter per cent to one per cent of the main voltage. Fig. 2 shows a device the connexions of which are shown in Fig. 1. A metallic-filament lamp a shunted by a resistance d, is connected in series with a resistance b across a low resistance c. The resistance b consists of iron wire, held between but insulated from metal disks e, and the resistances c, d consist of carbon blocks f, g respectively, the whole being held together by bolts i. In a modification, the lamp a, a carbon block resistance, and a constant resistance of Eureka metal or other material are all connected in parallel. In another modification, the lamp is simply connected across a constant resistance. In the apparatus shown in Fig. 1, a constant resistance may also be connected in parallel with the lamp a and carbon - block resistance d. Fig. 6 shows a device in which the indications of the lamp are supplemented by those of a pointer o connected to the pivoted armature j<1> of a coil j of constant resistance shunted by a carbon-block resistance k. The dial p of the pointer is illuminated by a lamp a, which may be the indicating-lamp. When the main circuit consists of two parts which may be connected in series or parallel, the indicating-device may be connected in series with one of them only.